Central Line occluded or sluggish?

Can you let me know what you do if a central line is blocked or sluggish?
what is the assessment you go though and what interventions would you do prior to calling the Dr.?
I am looking to see if we have a common practice for this or does everyone do a different thing?

P.S. Would appreciate if you can send me a protocol checklist if possible

Thanks
Amyna

try raisin the pt's arm above head